Process and installation for warm dehulling soya

ABSTRACT

The invention relates to a method for warm dehulling soya and other bean fruits and for subsequently grinding them, as well as to corresponding installation. The invention can simplify the process and the design of the installation. To this end, the fruits and heated/conditioned, double-ground, individualized on a baffle plate and the hulls are removed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application under 35 U.S.C. §120 ofPCT/CH00/00461, designating the United States, filed 30 Aug. 2000, whichis incorporated herein by reference.

BACKGROUND

The present invention relates to a process for warm dehulling soya beansand other bean fruits and subsequently grinding them, as well as aninstallation for carrying out said process.

The warm dehulling of soya or other bean fruits, for example inpreparing subsequent grinding, is known in general. DE-C-3544387describes such a dehulling process, in which the fruit are heatedthrough to the core at a certain temperature, are next subjected to ahot gas flow followed by removal of the hulls. The fruit are heatedthrough at 50° C. to 75° C. at least partially by means of contact heat.The temperature in the gas flow is raised to 90° C.

The fruit are subjected to the contact heat in a device with hotsurfaces, and to the hot gas flow on the other hand in a fixed orfluidised bed. The dehulling device can be a baffle dehuller downstreamof which another fluidised bed and/or a pneumatic sifter for removinghulls can be connected. Conditioning is carried out prior to grinding.

In a known, two-step grinding procedure, a first rough grinding stepemploying a pair of serrated rollers, followed by a pair of rubberrollers, is followed by a reducer and this is followed by a second roughgrinding step employing two pairs of serrated rollers.

SUMMARY

The present invention is directed to a process for warm dehulling ofsoya bean fruits or similar fruits or products, which avoids thedisadvantages of the prior art and enables the process to be carried outin a simplified manner.

An installation is provided for carrying out the process. A device isalso provided for dehulling the fruit and removing the hulls (hullseparator).

An exemplary process enables greater efficacy with fewer proceduralsteps. Conditioning and heatshock of soya or other bean fruits arefollowed by rough-grinding in a double-grinding unit and individualisingon a baffle plate, followed by separation of the hulls with aspiration.A fine grinding procedure can follow this step.

The process enables a protein-rich meal (47% to 48%, depending on theprotein content in the beans) to be produced.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described hereinbelow in greater detail in anembodiment with reference to a diagram, in which:

FIG. 1 illustrates a diagram of an exemplary process of an installationfor warm dehulling and grinding soya or the like,

FIG. 2 illustrates a cross-section of an exemplary hull separator.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In the following embodiment only the essential procedural andinstallation components are to be described in greater detail. Otherassociated procedural steps and installation components will emergenaturally from FIG. 1 with reference to the known prior art.

Whole soya beans enter steaming apparatus 1 and then a fixed orfluidised bed 2 for conditioning, as described for example inDE-C-3544387. The soya beans are heated in the steaming apparatus 1 bymeans of contact heat and in the fluidised bed 2 they are subjected tocontinuous heating in a hot gas flow at an average temperature of 70° C.to 90° C. On completion of heating the beans have a moisture content of10-11% Hulls which are already loosened are separated from the beansboth in the steaming apparatus 1 and in the fluidised bed 2 in a knownmanner.

The beans prepared enter a heating receptacle, not illustrated here,(interim depot) or directly enter a rough-grinding roller frame 3. Thisrough-grinding roller frame 3 contains two directly superposed rollerpairs 4, 5 which create a double-grinding step, as described for examplein EP-C-335925. The roller pairs 4, 5 display serrated rollers.

The ground beans then reach a baffle individualizer 6 and then a hullseparator 7, where the hulls are completely separated from the brokenbeans. The separated hulls can be subjected to further sifting in an airstream. This is then followed by a device for flaking in a flaking milland/or continued grinding in a fine milling device.

Referring to FIG. 2, the hull separator 7 comprises a substantiallycylindrical housing 701 having an upper material inlet 702 and a lowermaterial outlet 703, as well as a lower gas inlet 704 and an upper gasoutlet 705 for passing the crushed beans through in the countercurrent.In the process the beans are not only aspirated, but all loose hulls arealso carried away in the gas stream.

The material inlet 702 contains a delivery chute 706 via which the beans(and hulls) impact a first conical baffle 707 arranged concentrically tothe delivery chute 706 in a circular manner. Loose hulls and lightparticles are taken away by the gas stream flowing in the oppositedirection. On the other hand the bean constituents roll down the conicalsurface of the baffle 707 and fall into an underlying hopper 708.Projecting into the open floor 709 of the hopper 708 is anotherunderlying conical baffle 710. Due to the effect of gravity the beansand hull constituents roll from hopper 708 onto the conical surface ofthe second baffle 710 and from there into the other underlying hopper711. In the process other hull constituents can be removed with the gasflow.

Projecting underneath this hopper 711 into the floor 712 of the secondhopper 711 is another such baffle 713. A third and fourth baffle followin a similar manner. The fourth baffle 713 has a similar hopper with anopen floor 714. A fifth conical baffle 715 protrudes into this floor714, as described hereinabove. This displays beneath its conical surfacea cylindrical jacket surface 716, such that this baffle 715 covers theconcentrically arranged opening 717 of the gas inlet 704.

Only baffle 707 exhibits a closed conical baffle surface, as compared tothe tips of the upper baffles which are open at the top to enable thegas to flow through in the direction of the hopper and the overlyingbaffle.

The conical opening of the delivery chute 706 or parts of the deliverychute 706 can be height-adjusted to the baffle 707 (or the baffle also)in order to regulate the influx of beans as required.

Highly efficient aspiration of the bean goods and efficient separationof the hulls is achieved by this cascading impacting arrangement. Atleast two, three or more baffles can be provided in exemplaryembodiments.

It will be appreciated by those skilled in the art that the presentinvention can be embodied in other specific forms without departing fromthe spirit or essential characteristics thereof. The presently disclosedembodiments are therefore considered in all respects to be illustrativeand not restricted. The scope of the invention is indicated by theappended claims rather than the foregoing description and all changesthat come within the meaning and range and equivalence thereof areintended to be embraced therein.

1. A process for warm dehulling of bean fruits and subsequent grinding,comprising: warming the fruits; and grinding the bean fruits andseparating hulls from the bean fruits, wherein the grinding is carriedout by means of one double-milling step, followed by individualising thebean fruits on a baffle plate and aspiration with removal of the hulls.2. The process as claimed in claim 1, comprising: flaking or finegrinding the bean fruits following aspiration.
 3. The process as claimedin claim 1, wherein two-step rough-grinding takes place during thedouble-milling.
 4. The process as claimed in claim 1, comprising:passing a gas flow through a mixture of the ground beans and hulls in acountercurrent for hull separation; and aspirating and removing thehulls from the mixture by a cascading impacting effect of the mixture.5. An installation for warm dehulling of bean fruits and subsequentgrinding, according to the process of claim 1, the installationcomprising: a steaming apparatus and/or a fluidised bed for heating thebean fruits; a rough-grinding mill for double-milling the bean fruits;and a baffle individualizer connected downstream of the rough-grindingmill followed by a hull separator.
 6. The installation as claimed inclaim 5, comprising: a flaking mill and/or fine milling device isconnected downstream of the hull separator.
 7. The installation asclaimed in claim 5, wherein the rough-grinding mill contains twodirectly superposed roller pairs with serrated rollers.
 8. Theinstallation as claimed in claim 5, wherein the hull separator containsbaffles arranged to cascade over one another with conical bafflesurfaces, whereby between every two baffles hoppers are arranged, intoopen floors of which each of the underlying baffles protrudes.
 9. Theinstallation as claimed in claim 8, wherein at least two baffles areprovided.
 10. The installation as claimed in claim 9, wherein thebaffles are arranged concentrically to a center axis of the hullseparator.
 11. (canceled)
 12. The process as claimed in claim 1, whereinthe warming is performed by contact heat and/or in a hot gas flow.